iPod has album artwork sync problems

My iPod syncs music from iTunes no problem and plays fine, the problem is with the album artwork. On the main menu where you see the album artwork appear and it moves slowly across the screen, all album artwork is there.

But on the other menus mostly it doesn’t appear. I synced about eight albums and only two appear in the cover flow and album menus, and on the songs menu the art appears infrequently. I have tried resetting by pressing the hold and menu buttons simultaneously but to no avail. I erased the music and did it again and it still didn’t work, and the same albums worked and didn’t work as per the first time.

Adding to that, I have low speed 1.1 USB ports instead of the recommended 2.0, and I wondered if that may be an issue. Or could it be related somehow to the computer? Would be grateful for any advice.